Method and apparatus for treating mixtures to make or break emulsions



Oct. 23, 1951 G STREZYN'SK] 2,572,287

. METHOD AND APPARATUS FOR TREATING MIXTURES TO MAKE OR BREAK EMULSIONS Filed Aug. 28, 1946 4 Sheets-Sheet l INVENTOR GEORGE. QZSZREZ'Y/VSK! ATTO R Y Oct. 23, 1951 G. J. STREZYNSKI METHOD AND APPARATUS FOR TREATING MIXTURES TO MAKE OR BREAK EMULSIONS 4 Sheets-Sheet 2 Filed Aug. 28, 1946 INVENTOR 620x05 J SIREZWISK] 1951 I G J. STREZYNSKII 2,572,287

METHOD AND APRARATUS FOR TREATING MIXTURES TO MAKE OR BREAK- EMULSIONS Filed Aug. 28, 1946 4 SheetsSheet 3 I N V E N TO R GEORGE cl SZ'JEEZYNSJU Q QQQ ATTO EY Oct. 23, 1951 G J. STREZYNSKI 2,572,287

METHOD AND API ARATUS FOR TREATING MIXTURES TO MAKE OR BREAK EMULSIONS Filed Aug. 28, 1946 4 Sheets-Sheet 4 INVENTOR 5.9 4* GEORGE JJZREZYN KI Patented Oct. 23, 1951 METHOD AND APPARATUS FOR TREAT- ING MIXTURES TO MAKE OR BREAK EMULSIONS George J. Strezynski, Chicago, Ill., assignor to The De Laval Separator Company, New York, N. Y., a corporation of New Jersey Application August 28, 1946, Serial No. 693,537

Claims. 1

This invention relates to the centrifugal treatment of mixtures to break up small particles therein, to make or break emulsions, and the like. More particularly, the invention has reference to an improved method and apparatus for this purpose, in which centrifugal force is utilized to cause a vibrating action on the mixture as it discharges from the locus of centrifugal force.

Centrifugal force has been utilized heretofore in apparatus for making a more or less permanent mixture, generally called an emulsion, of two or more materials, such as water and oil. In such apparatus as commonly constructed, a rough mixture of the two materials is discharged by centrifugal force between plates revolving at high speed and arranged in close proximity to each other to provide a discharge orifice in the form of a narrow slit, which may be in the order of onethousandth of an inch in width. An apparatus of this character is disclosed in U. S. Patent No. Li i -90, issued to M. Leitch et al, on July 6, 1915. While this prior apparatus has been effective for emulsifying materials and has enjoyed considerable use, it has been found that small particles of the raw materials sometimes collect in the narrow discharge passages of the emulsifying elements and eventually tend to clog them and to stop the operation of the apparatus.

One object of the present invention, therefore, resides in the provision of an improved centrifugal method and apparatus for treating mixtures to break up small particles therein, to make or break emulsions, and the like, by which the mixture is discharged through a narrow outlet from the locus of centrifugal force without clogging the outlet.

Another object is to provide a method and apparatus of the character described, in which the discharge outlet from the locus of centrifugal force is alternately opened and closed with a pounding action to prevent clogging and also to break up particles of material discharging through the outlet, whereby the invention may be used to advantage for making emulsions and also for breaking emulsions by the pounding action on the suspended particles.

A further object is to provide a method and apparatus of the character described, in which the alternate expanding and contracting of the discharge outlet, with or without the accompanying pounding a tion on the discharging mixture, is effected rapidly and automatically under control of the centrifugal pressure of the mixture in the locus of centrifugal force.

Still another object is to provide an apparatus 2 of the character described having automatic means for insuring that the mixture will be discharged only under a large hydrostatic pressure due to centrifugal force.

An additional object is to provide an apparatus of the character described having a deflecting wall against which the discharging material is sprayed at high. velocity, thereby acting to break up particles in the mixture.

Another object is to provide a methodand apparatus of the character described which are especially adapted. for treating milk products to break cream emulsions of high fat content as a step in concentrating butter oil, to emuls'ify a mixture of milk ingredients for reconstituting cream, and the like.

According to the invention, the mixture to be treated, such as a mixture of oil and water, is fed into a locus of centrifugal force, or centrifugal chamber, where a body of the mixture is accumulated in the peripheral portion of the chamber adjacent a restricted discharge outlet. The outlet may be in. the form of a narrow slit between two working surfaces of a pair of housing members defining the chamber, one of the members being reciprocable relative to the other to expand and contract the outlet. As the mixture accumulates in the chamber and builds up toward the axis of rotation, the action of centrifugal force causes it to exert an increasing pressure on. the reciprocable housing member, and when this pressure attains a relatively high value, the outlet expands to permit discharge of the mixture by centrifugal force at a rate in excess of the rate of feed to the chamber. The centrifugal pressure of the mixture on the reciprocable member then decreases to a relatively low value to permit the reciprocating member to contract the outlet, whereby another body of mixture accumulates in the chamber and the cycle is repeated. The arrangement may be such that in this contraction of the outlet, the working surfaces of the housing members are brought together with a pounding action, thereby tending to disintegrate particles of material between these surfaces.

Thus, the expansion and contraction of the outlet, which may be accompanied by a pounding action on the discharging material, are effected automatically under control of the centrifugal pressure of the alternately accumulating and receding body of mixture in the chamber- Preferably, the reciprocable housing member is arranged to expand and contract the discharge outlet rapidly by changes in the centrifugal pressure of the mixture on this member within a high pressure range, so that the mixture is discharged only under a large hydrostatic pressure due to centrifugal force, and the operating cycle is repeated at short intervals to effect a rapid vibration of the reciprocable member.

For a better understanding of the invention, reference may be had to the following detailed description taken in conjunction with the accompanying drawings, in which Fig. 1 is a vertical sectional view of part of an apparatus made in accordance with the invention;

Fig. 2 is a horizontal sectional view on the line 22 in Fig. 1;

Fig. 3 is a vertical sectional view of part of a modified form of the apparatus, and

Fig. 4 is a horizontal sectional view on the line 44 in Fig. 3.

Referring to Figs. 1 and 2, the apparatus comprises a stationary frame [0 and a driving spindle I I supported for rotation in the frame in suitable bearings (not shown) Mounted on the upper end portion of the spindle is a housing assembly comprising three annular housing members l2, l3

and 14. The lower housing member M is fitted closely around the spindle and is seated on a shoulder IS on the spindle. The member I4 is recessed to provide an annular feed chamber is which communicates with a bore in the upper end portion of the spindle through ports I? in the spindle wall, the part of the spindle below the ports I! being solid.

The intermediate housing member l3 has a central portion Isa projecting downwardly into the feed chamber I6 and having a close sliding fit with the outer wall of the feed chamber, as shown at [317. The intermediate member 13 is spaced from the spindle, and the inner wall of its central portion 53a tapers upwardly to an inlet (8 between the feed chamber and a centrifugal chamber 19 defined by the housing members l2 and The chamber 19 extends outwardly to a greater radius than feed chamber [6 and is formed by recessing the bottom of upper housing member 12 and the top of intermediate member IS. A nut 20 is screwed on the upper end of the spindle to clamp the housing member I2 against a shoulder on the spindle, the member I2 being also keyed to the spindle, as shown atZl At the peripheral portion of the centrifugal chamber IS, the housing members l2 and B have interengageable working surfaces 22 which define an outlet from the centrifugal chamber. The

working surfaces 22 are urged together by an annular gasket 23 made of resilient material, such as rubber, and arranged near the sliding fit (3?). The gasket 23 is interposed between the bottom of feed chamber l6 and the lower end of the central portion I3a of the intermediate housing member and is held under compression so that it acts to close the outlet formed by the working surfaces 22. In this position of the intermediate member 13, there is a clearance at 22a. between the upper end of the lower housing member [4 and the overlying surface of the intermediate member l3, this clearance being too small to be illustrated accurately but being, for example, in the order of one-hundredth of an inch. The

intermediate housing member 13 is thus adapted toreciprocate axially between the upper and lower housing members l2 and i4, whereby the outlet 22 is alternately expanded and contracted.

The reciprocable housing member [3, as shown, is provided on its peripheral portion with an uping through the outlet.

4 wardly projecting lip 24 extending around the outside of outlet 22 in spaced relation thereto.

A cover assembly 25 is mounted on the frame it around the rotating parts and forms a receiver 26 for collecting the material discharged through the outlet 22. The receiver 26 may be provided with a suitable discharge spout (not shown). On top of the cover assembly 25 is a hopper 27 for receiving the material to be treated, the hopper having a central bottom opening communicating with a stationary feed tube 28 extending down into the hollow spindle l I.

In the operation of the apparatus, the material to be treated, which may be a rough mixture of butter oil, water and milk powder to be emulsified for making cream, is fed continuously from the hopper 21 through feed tube 28 into the hollow spindle H, the spindle being rotated at high speed, for example, 8,000 to 16,000 R. P. M., by a suitable motor (not shown). The resulting centrifugal force causes the mixture to flow outwardly from the interior of the spindle through ports ll into the feed chamber or first centrifugal locus It. The mixture accumulates in the peripheral portion of chamber l5 and, due to centrifugal force, exerts an upward pressure on reciprocable member [3 acting to hold the surfaces 22 together and close the outlet. The mixture finally overflows the inner edge of the central housing portion [3a. and passes through inlet 18 into the second centrifugal chamber or locus l9. In the latter chamber, the mixture flows outwardly from inlet (8 under centrifugal force and accumulates in the peripheral portion of the chamber.

As the body of mixture in chamber [9 builds up toward the axis of rotation, it exerts an increasing downward pressure on the pressure controlled surface l3c of the intermediate housing member l3, due to the centrifugal force acting on the mixture. Since the chamber 19 is of larger radius than feed chamber 16, this increasing pressure on surface I30 will ultimately overcome the biasing action of gasket 23 and the upward pressure of the mixture against member I3 in chamber 16, whereupon the member (3 moves downwardly against the surface 22a of the lower housing member Id. Thus, the gasket 23 is compressed and the working surfaces 22 are separated so as to open the outlet which they define, for example, to a width of about one-hundredth of an inch.

In this lowermost position of the reciprocating member l3, the mixture is discharged by centrifugal force from chamber l9 through outlet 22 at a maximum rate which exceeds the rate of feed of the mixture through inlet 18. Accordingly, the inner level of the mixture in chamber [9 recedes outwardly, with the result that the axial pressure on the surface I3 2, due to centrifugal force on the mixture, is reduced. When this pressure is reduced to the point where it is overcome by the sure of the mixture on reciprocating member l3,

the latter is forced upwardly to clamp the working surfaces 22 together, thereby tending to pound and disintegrate any particles discharg- At the same time, the resulting contraction of outlet 22 stops the discharge so that the mixture again accumulates in the peripheral portion of the centrifugal chamber i 9 and the cycle is repeated.

By properly controlling the radial dimension of feed chamber 16, the rotational speed of spindle H, the effective area of the part l3a influenoed by the mixture pressure inieed. chamber 15, and the compression of gasket 23,. the member [3 maybe made to hold the discharge outlet open only as long as there is a large hydrostatic pressure of the mixture'on surface I30 due to centrifs ugal force. Thus, the apparatus will insure. that the mixture is discharged only under heavy pressure to enhance the mixing action and spray the discharge at high velocity against lip 2 4', so thata further breaking up and dispersion of particles is obtained. Also, by properly controlling the above operating factors in relation to the radial dimension of chamber [9, the rate of feed to-chamber t9, the size of the particles of the emulsion or the component materials, and the discharge rate from chamber t9 (the maximumopening of outlet 22), the member It may be made to reciprocate at a rapid rate so that the working surfaces 22 open and close the outlet with a chattering action. I have found that good results may be obtained by providing centrifugal pressures of several hundred toseveral thousand pounds per square inch of the mixture on surface l3c and reciprocating the member 3 at a rate in the order of cycles per-second, for treating certain mixtures, as, for example, to break up particles in cheese mixes for obtaining a uniform mixture prior to separation the curds, to make emulsions, as in reconstituting cream from butter oil, milk powder and water, and to break emulsions, as in the production of butter oil from cream.

The width of the Working surfaces 22 and the vibration rate of member [3 may be such that a substantial part of the discharging mixture is pounded between the working surfaces. l h'e lower working surface 22', as shown, serves also to accelerate the opening of the outlet to its maximum width, since the discharging mixture exerts an additional downward thrust on this surface when the outlet commences too-pena- From the foregoing, it will be'apparent that the apparatus is fully automatic in operation, the opening and closing of the discharge; outlet 22 and the resulting pounding action on the discharging material being controlledby changes in the centrifugal pressure of the alternately accumulating and receding body of mixture on the pressure controlled surface |-3c. The reciprocating means includes the pressure controlled surface [30 and also the-surface of the part ISa subjected to the counteracting pressure of mix ture in feed chamber l6, and the resilient gasket 23. The reciprocating action of the intermediate housing member 13 not only serves to prevent.

clogging of the outlet by particles "of the discharging material but also tends to br'ealr up these particles and obtain an intimate and homogenous mixture of the discharging material. Any disintegrated particles tending to adhere to -the surfaces 22, after each pounding action the're- For breaking emulsions, such as cream, and. for homogenizing cheese mixes, I prefer to use a modified form of the apparatus in which .the; housing assembly also'contains an outer chamber for receiving the mixture discharged from the outlet, to prevent aeration of the mixture and,

hydrostatic also to preventit from. going back into emulsion.

The modified apparatus, as shown. in Figs-.. 3 androunds the spindle and is seatedon a shoulder 32a, the: collar in turn. supporting a ring 33 fitted closely around the collar and secured thereto in any suitable manner, as by welding. A main housing made up of two annular, complementary sections 34 and 34a is. mounted on and rotates with the spindle 31. The outer portion of the mainhousi-ng 34', 34a is enlarged and rests upon the ring 33, while the'inner portion 35- ofthe housing is reduced and rests upon a gasket. 35 on the flanged end of collar 32. A nut'a'l' is screwed on the: top of the spindle and serves to clamp the main housing on: the collar 32. andr'ing 33. The reduced portion 35 of the housing forms an annular feed passage--38- communicating atits inner end with the interior of the spindle and at its outer end with the interior of: the enlarged portion of the housing: through restrictedopem ings -39;

Within the outer or enlarged portion of themain housing 34, 34c are two annular reciprocable housing members 4|, 4m which are generr- I ally' trough-shaped .in cross section, the upper member 4| being inverted so that its open end is adjacent the open end. of the lower member '41 a. The: main housing 34 34a is internally recessed at the top and bottom and. defines withther'housing members.- and 410' two annular centrifugal chambers 42 and. 42a, respectively; Attherouter peripheries of these chambers, the main. housing and the .reciprocable members 4'! and 4:11;

have interengageable working surfaces. 43 and 43a, respectively, providing outlets which. open and; close. in the reciprocation of the members. The surfaces 4-3 and 43a areinormally' urged to:-

gether to close the outlets, by biasing means in the form of flexible sealing. rings 4s and 415a,; re, spectively', backed by substantially non-yielding washers 4.4 and 44a, respectively, thewashers extending inwardly between the members 41: and 4m and between the housing sections. 34? vand 34a, and being seated at their inner edges against the periphery of the spindle. The outer edge portions of washers 44 and 44a are "slightly curved diverging. relationv and make sliding contact againstv the outer walls of the reciprocable members 4 and- A'l'a, respectively. The sealing free reciprocating motion of the members. 41-, 4 id.

The washers 44 and 44a and their respective housing m mbers 55 and. n; and rings 45..d6rl

define separateannular feed chamberszcommunieating through restricted "inlets '41 and He a-t the inner ends of the feed chambers, with the'cen- 'trifugal chambers 42 and 42a, the latter extend;-

ing outward to the outlets 43 and 43a. at a substantially greater radius than the feed chambers. The feed chambers also communicate with feed passage 38 on opposite sides of the washers, through spaces between the housing members 4| 4 a and the washers and through the openings 39, it being understood that these spaces and openings are formed by notching the edges of housing members 4|, Ma and housing sections 34, 34a adjacent the washers. Thus, the centrifugal chambers 42 and 42a are in constant communication with feed passage 38 during reciprocation of members 4| and Ma. The inner portions of the washers may be provided with openings 44b connecting the upper and lower sections into which the feed passage 38 is divided by the washers.

At the outer periphery of the main housing the joint between the two sections 34, 34a, is sealed by a thin annular insert 48 which is T-shaped in cross-section, the head of the insert being seated against the inner surface of the outer wall of the housing. This wall, together with the outer walls of the reciprocable housing members 4|, 4la, forms an outer chamber 49 for receiving the mixture discharged through outlets 43, 43a. The chamber 49 has peripheral outlets 50 near the insert 48 and offset axially from outlets 43, 43a.

The frame 30 supports a cover assembly 52 forming a chamber 53 for collecting the mixture discharged through outlets 50, the collecting chamber 53 having a bottom outlet communicating with a discharge spout 54. The cover assembly in turn supports a stationary axial feed tube 55 extending into the open end of the hollow spindle.

The operation is similar in general to that of the apparatus shown in Figs. 1 and 2. The mixture flows into the rotating spindle from feed tube 55 and is thrown outwardly through feed passage 38 and openings 39 into the feed chambers in housing members 4|, 4|a. There the mixture accumulates in the peripheral portions of the feed chambers and finally overflows through inlets 41,

41a into the centrifugal chambers 42, 42a, where V the mixture again accumulates in the peripheral portions, the outlets 43, 4301. being held closed by the biasing action of the flexible rings 46, 46a and the liquid pressure in the feed chambers containing these rings. As the mixture accumulates I in the chambers 42, 42a toward the axis of rotation, the action of centrifugal force causes it to exert an increasing pressure on the adjacent pressure controlled surfaces of members 4|, 4|a, and

when this pressure exceeds the counteracting force of the rings 46, 46a and the liquid pressure in the feed chambers containing the rings, the resulting movement of members 4|, 4|aopens the "outlets 43 and 43a the maximum desired width, for example, about .01". The mixture then discharges through the outlets under high pressure due to' centrifugal force, until the bodies of mixture in chambers 42, 42a recede outwardly to the point where their centrifugal pressure on members 4|, 4|a is overcome by the counteracting .biasing pressure, whereupon the members 4|, 4 Id return to their initial positions to close outlets '43 and 43a and at the same time pound any particles of the mixture between the surfaces defining the outlets; Thus, the members 4| and Ma are reciprocated automatically.

The mixture discharged through outlets 43 and 43a strikes the outer wall of the main housing 34, 34:; at high velocity and then passes toward the central portion of out'erchamber 49, from which it is discharged through outlets 50 into the stationary collecting chamber 53. The outer centrifugal chamber 49 acts to prevent aeration of the mixture from chambers 42 and 42a and to prevent re-emulsifying of the mixture when it is desired to break an emulsion, as might otherwise occur if the mixture were sprayed directly from the outlets 43 and 43a into the collecting chamber 53.

It will be understood that the washers 44, 44a, instead of being rigid, could be made flexible with a spring action and arranged so that their outer edge portions move with the reciprocating members 4|,- 4|a, in which case the biasing action on the members 4|, 4|a tending to close the outlets would be obtained entirely from the spring action of the washers. The latter construction, however, has the disadvantage that its operation would be impaired by mechanical failure of the spring washers. Also, it will be understood that while I have shown only two sets of reciprocating members and associated parts, a larger number may be employed if desired, preferably by arranging the parts in tiered fashion.

I have found that by the practice of my invention, dairy cream may be concentrated to as high as 99 percent of butterfat or higher, more readily than has been possible with prior practices. In centrifuging ordinary cream in the usual types of centrifugal apparatus, it is generally impossible to obtain a butterfat concentration substantially in excess of percent, unless some other means are used to release the fat occluded by the curd or proteins. Prior methods for releasing the fat are rather involved, time-consuming and expensive. However, with the present invention, the cream may be concentrated in an ordinary centrifuge to a butterfat content of '78 to 80 percent, and then passed directly into an apparatus such as that shown in Figs. 3 and 4, where the, extrusion of the cream through outlets 43 and 43a under high centrifugal pressures, preferably with a rapid and intense pounding action of the working surfaces defining these outlets, serves to rupture the membranes containing the fat globules and thereby break the emulsion. The material may then be readily concentrated, by recentrifuging, to a fat content of 99 percent or greater.

I have also found that the present invention lends itself admirably to reconstituting cream from butterfat, skim milk powder and'water. As an example, 8 pounds of butterfat are melted and heated to about 110 F., and 2.8 pounds of milk powder are added to 29.2 pounds of water and heated to about 110 F. The melted butterfat and the milk solution are mixed together and agitated and then fed at a temperature of about F. into the apparatus, which may be of the form shown in Figs. 3 and 4. There the material is intimately mixed and emulsified by the pounding and extruding action under high centrifugal pressures, and is discharged from the apparatus in the form of cream.

The mechanics of the reciprocating movemen of the apparatus are largely dependent upon the size of the particles of the components of the emulsion or other material being treated, and upon the size of the narrow slit opening (22 or 43, 43a) Usually, the size of these particles will vary. For instance, they may varyfrom .001 to .010". If the slit opening is .006, then this opening will allow all smaller particles to go through but will hold back the larger particles. This, will gradually clog up the slit opening and result in increasing the level in thachamber aera it-er- 42: 2 $9 a e press re xerted b this eree-sih 'level w et t x thetlit ehe ii s the th the l r e r e t ta rus ing through the opening. However, as these es th e t e Op n n t evel, chamber decreases and the opening tends e. This action is continuous andmay reg a vibration in the'order of 1 5 cycles per sepond, or the vibration rate may decrease to as low as-g cycles per second or increase to an even is eh ert erher'e h d t a '..t w l. h u de s t e i venti n ma he us s ta et u s s than those d e h that the t r f w pressures a whi h t e hitsitre s isch d he r t e hi eh i r a he reundih 5 09, and h h mum w th to which th nar w eiee 'se out ts ar eh emay be varied to suit regui'rements. Als 'while I de ert-hee t u e s ti t he as e1 he ee hhlete ehi h aeh p t n e el t t W e uhders eee a th ir s s h e h he 9 m" a e-ta whe eb th m re w l be, d schar eti heh l a a a yin rate i 1- A 35 3??! $9 9.31%? 9? r a th m hit er t, l p wder a d ter w ch 7 h -t es h tins a d mi in the hgtt h t hi rev e an ate ie d h e heated m xtu e t a leeus ce r rt in p riodic e h aeeumulatins body of th matu e ih iph ral por ion of th lo u o i eas h m xu ressur the ein du o eehtri-tush eree, isch r g th mixture b ce tr f ga f rce n a closely confined st ea from the er p eral portion of the locus at a re at v l hi h ate in xcess of said feed, to decr ase th m xtu e p e sure in the locus .due to centrifu al or e an cutting down the discharge rate from the :locus to less than said feed rate to thereby accumulate another body of mixture in the peripheral portion thereof, and controlling the variations the discharge rate by said changes in the centrifugal pressure of the mixture in the locus, said dischargeat a relatively high rate andsaid cut: ting down of the discharge rate being repeated alternately to efiect a rapid vibrating action .on the mixture.

2. Apparatus for treating mixtures to make or break emulsions, and the like, which comprises a housing member rotatable about an axis, a second housing member rotatable about .the axis and defining with the first member a centrifugal chamber having near said axis a restricted inlet for the mixture, the first housing member being reciprocable relative to the other and having a pressure controlled surface partly defining the chamber and disposed at .a greater radius from said axis than the inlet, the membersthaving working surfaces disposed at a greater radius from the axis than said pressure controlled sur: ace and prov in n outlet which expands and contract i the r r a ion o s id firs meme b r means in lud ng Said p ess re controlled sgriae and rab e ah ehratiea ly hy ih he eeht i hse es h 9 m xtu e in the chamber to reciprocate said first member for alternately expanding theoutlet to the mixture at a maximum rate and then contrac the outlet to reduce the discharge rate through the outlet, and means, including a second cen' trifugal chamber partly definedby said reciprocating member, for feeding the mixture through he in e a a ra es th n said max mum elischarge rate when the outlet is expanded but reate t an sa redu ed d sch r e the outlet is contracted, whereby he mixture alternately accumulates and recedes in the chamber to vary the centrifugal pressure of the mixture on said pressure controlled surfacgsaid second chamber being coaxial with the first chamber and havinga surface forming part of he e oc in mea s and acted upon b ture under centrifugal force in the second fchame her to bias the reciprocable member toward the other member and contract the outlet.

' 3. Apparatus for treating mixtures to malie or break emulsions, and the like, which comprises a honsingm ember rotatable about an axi 1 a d housing member rotatable about the s and efining with the first'member a'centrif a1 chamber having near said axis a restricted i let for'the mixture, the first housing member being reciprocable relative to the other and having a pressure controlled suriace partly defining the chamber and disposed a greater radiusirom said'axis thanthe inlet, the members hav'ng working surfaces disposed at a greater ra from the axis than said pressure controlled sur face and providing an outlet which expands and contracts in the reciprocation of said first arena: ber, means including said pressure controlled surface and operable automatically bychanges in the centrifugal pressure of mixture in the chamber to reciprocate said first member igr alternately expanding the outlet to discha ge the mixtureata maximum rate and then contracting the outlet to reduce the discharge rate through the outlet, a third rotary housing member have ing a sliding fit with part of said first member and defining therewith a feed chamber communi'; eating with said inlet, the reciprocating me including a compressible gasket between said and third housing members for sealing the slid: ing f t and urging said working surfaces tog and means including said feed chamber for ie u ing the mixture through thejinlet at a rate ss than said maximum discharge rate when the outlet is expanded but reater than said red discharge rate when the outlet is contrac whereby the mixture alternately accumulates and recedes in the chamber to yary'the centrifugal pressure of the mixture on said pressure con: trolled surface.

Apparatus for treating mixtures to malge or break emulsions, and the like, which comprises a housing member rotatable about an axis, a second housing member rotatable about the axis and def ning with the first member a centrifugal chamber having near said axis a restricted inlet for he m x ur e fi s housing memb r being re ciprocable relative to the other and h, ing a pressure controlled surface partly defini g the chamber and disposed at a greater radiu from said axis than the inlet, the members having working surfaces disposed at a greater rad us from the axis than said pressure controlled su t:- faceand providing an outlet which expands and ont ac s i th re pro a n o s id fi s mem;

ber, means including said pressure controlled su f an o era le automa a y by ehahgesih the centrifugal prcssureof mixture in the chamber to reciprocate said first member for al r; nately expanding the outlet to discharge the 1xture at a maximum rate and then contracting the outlet to reduce the discharge rate through the outlet, a hollow axial spindle ior support'ng' and rotating the housing members, said members being of generally annular form and said first m mber being c ncen ri With but spaced r h,

, the spindle, the other member being concentricwith the spindle and mounted thereon, a third annular housing member mounted on the spindle and at least partly defining a feed chamber communic'ating with the interior of the spindle and with the inlet, said first housing member having a portion partly defining said inlet and extending into the feed chamber with a sliding fit with said third member, the reciprocating means including an annular compressible gasket disposed between said first and third housing members in position to seal the sliding fit, and means including the spindle and said feed chamber for feeding the mixture through the inlet at a rate less than said maximum discharge rate when the outlet is expandd but greater than said reduced discharge rate when the outlet is contracted, whereby the mixture alternately accumulates and recedes in the chamber to vary the centrifugal pressure of the mixture on said pressure controlled surface.

5. Apparatus for treating mixtures to make or break emulsions, and the like, which comprises a housing member rotatable about an axis, a second housing member rotatable about the axis and defining with the first member a centrifugal chamber having near said axis a restricted inlet for the mixture, the first housing member being reciprocable relative to the other and having a pressure controlled surface partly defining the chamber and disposed at a greater radius from said axis than the inlet, the members having working surfaces disposed at a greater radius from the axis than said pressure controlled surface and providing an outlet which expands and contracts in the reciprocation of said first member, means including said pressure controlled surface and operable automatically by changes in the centrifugal pressure of mixture in the chamber to reciprocate said first member for alternately expanding the outlet to discharge the mixture at a maximum rate and then contracting the outlet to reduce the discharge rate through the outlet, and means for feeding the mixture through the inlet at a rate less than said maximum discharge rate when the outlet is xpanded but greater than said reduced discharge rate when the outlet is contracted, whereby the mixture alternately accumulates and recedes in the chamber to vary the centrifugal pressure of the mixture on said pressure controlled surface, said second housin member containing the reciprocable housing member and at least partly defining therewith an outer chamber for receiving mixture discharged through said outlet from the first chamber, said outer chamber having a peripheral outlet for dischargin mixture therefrom and displaced axially from said first outlet.

6. Apparatus for treating mixtures to make or break emulsions, and the like, which comprises a housing member rotatable about an axis, a second housing member rotatable about the axis and defining with the first member a centrifugal chamber having near said axis a restricted inlet for the mixture, the first housing member being reciprocable relative to the other and having a pressure controlled surface partly defining the chamber and disposed at a greater radius from said axis than the inlet, the members having working surfaces disposed at a greater radius from the axis than said pressure controlled surface and providing an outlet which expands and contracts in the reciprocation of said first member, means including said pressure controlled surface and operable automatically by changes in the centrifugal pressure of mixture in the chamber to reciprocate said first member for alter- 12 nately expanding the outlet to discharge the mixture at a maximum rate and then contracting the outlet to reduce the discharge rate through the outlet, a third rotary housing member reciprocable relative to the other housing members and defining with said second member a second centrifugal chamber having near said axis a restricted inlet for the mixture, said third member having a pressure controlled surface partly defining the second chamber and disposed at a greater radius from said axis than the second inlet, the second and third members having working surfaces disposed at a greater radius from the axis than said second pressure controlled surface and providing an outlet. which expands and contracts in the reciprocation of the third member, the second housing member containing said reciprocable members and at least partly defining therewith an outer chamber for receiving the discharge from said outlets, the outer chamber having a peripheral outlet for discharging mixture therefrom and displaced axially from said first outlets, the reciprocating means being operable to reciprocate both reciprocable members and including said pressure controlled surfaces and a pair of superimposed spring elements acting to bias the reciprocable members toward said second member to contract the outlets from the centrifugal chambers, each spring element defining with one of the reciprocable members a feed chamber communicating with the inlet to the adjacent centrifugal chamber, and means including said feed chambers for feeding the mixture through the inlets at a rate less than said maximum discharge rate when the variable out-' lets are expanded but greater than said reduced discharge rate when the variable outlets are contracted.

7 Apparatus for treating mixtures to make or break emulsions, and the like, which comprises a housing member rotatable about an axis, a second housing member rotatable about the axis and defining with the first member a centrifugal chamber having near said axis a restricted inlet for the mixture, the first housin member being reciprocable relative to the other and having a pressure controlled surface partly defining the chamber and disposed at a greater radius from said axis than the inlet, the members having working surfaces disposed at a greater radius from the axis than said pressure controlled surface and providing an outlet which expands and contracts in the reciprocation of said first member, a spring element defining with reciprocable member a feed chamber communicating with said inlet, said element acting to bias the reciprocable member toward the other member to contract the outlet, said spring element and pressure controlled surface being operable automatically by changes in the centrifugal pressure of mixture in said first chamber to reciprocate said first member for alternately expanding the outlet to discharge the mixture at a maximum rate and then contracting the outlet to reduce the discharge rate through the outlet, and means including said feed chamber for feeding the mixture through the inlet at a rate less than said maximum discharge rate when the outlet is expanded but greater than said reduced discharge rate when the outlet is contracted, whereby the mixture alternately accumulates and recedes in said first chamber to vary the centrifugal pressure of the mixture on said pressure controlled surface. I

8. A method for treating mixtures to break up small particles therein, to make or break emulsions, and the like, which comprises feeding the mixture to a locus of centrifugal force, in periodic sequence accumulating a body of the mixture in the peripheral portion of the locus to increase the mixture pressure therein due to centrifugal force, discharging the mixture by centrifugal force in a closely confined stream from the peripheral portion of the locus at a relatively high rate in excess of the rate of said feed, to decrease the mixture pressure in the locus due to centrifugal force, and cutting down the rate of discharge from the locus to less than said rate of feed to thereby accumulate another body of mixture in the peripheral portion thereof, controlling the periodic variations in the discharge rate by said changes in the centrifugal pressure of the mixture in the locus, and pounding the discharging mixture periodically and simultaneously with cutting down the rate of discharge from the locus.

9. A method for treating mixtures to break up small particles therein, to make or break emulsions, and the like, which comprises feeding the mixture to a locus of centrifugal force, in periodic sequence accumulating a body of the mixture in the peripheral portion of the locus to increase the mixture pressure therein due to centrifugal force, discharging the mixture by centrifugal force in a closely confined stream from the peripheral portion of the locus at a relatively high rate in excess of the rate of said feed, to decrease the mixture pressure in the 'locus due to centrifugal force, and cutting down the rate of discharge from the locus to less than said rate of feed to thereby accumulate another body of mixture in the peripheral portion thereof, and controlling the periodic variations in the discharge rate by said changes in the centrifugal pressure of the mixture in the locus, said 14 discharge being at a relatively high rate and said cutting down of the discharge rate being repeated alternately at a rate in the order of fifteen cycles per second to effect a rapid vibrating action on the mixture.

10. A method for treating mixtures to break up small particles therein, to make or break emulsions, and the like, which comprises feeding the mixture to a locus of centrifugal force, in periodic sequence accumulating a body of the mixture in the peripheral portion of the locus to increase the mixture pressure therein due to centrifugal force, discharging the mixture by centrifugal force in a closely confined stream from the peripheral portion of the locus at a relatively high rate in excess of the rate of said feed, to decrease the mixture pressure in the locus due to centrifugal force, and cutting down the rate of discharge from the locus to less than said rate of feed to thereby accumulate another body of mixture in the peripheral portion thereof, controlling the periodic variations in the discharge rate by saidchanges in the centrifugal pressure of the mixture in the locus, feeding the mixture to a second locus of centrifugal force before feeding the mixture to said first locus, and utilizing the centrifugal pressure of the mixture in said second locus to cut down the discharge rate from the first locus.

GEORGE J. STREZYNSKI.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,145,600 Leitch et al. July 6, 1915 1,338,996 Norcross May 4, 1920 2,273,835 Cornell Feb. 24, 1942 

